Possible causes – Faulty Rear Heated Oxygen Sensor Bank 1– Rear Heated Oxygen Sensor Bank 1 harness is open or shorted– Rear Heated Oxygen Sensor Bank 1 circuit poor electrical connection– Intake air leaks– Exhaust gas leaks– Inappropriate fuel pressure– Faulty fuel injectors Tech description Replacing the Rear Heated Oxygen Sensor Bank 1 usually takes…